NDLI: A photometric invariant and shape constraints at parabolic points

Content Provider	IEEE Xplore Digital Library
Author	Wolff, L.B.
Copyright Year	1990
Description	Author affiliation: Dept. of Compt. Sci., Columbia Univ., New York, NY, USA (Wolff, L.B.)
Abstract	Using rigorous methods the authors have shown that the invariant direction of isophotes at parabolic points is the projection of the principal direction of zero curvature onto the image plane. They have gone beyond considering the limited case of pure orthographic projection and have shown under what conditions this photometric invariance property breaks down and is best approximated in perspective images, and for a nondistant light source. In addition to giving experimental evidence supporting their claim about how isophotes are parallel to the direction of zero curvature at parabolic points, the authors suggest possible applications of this geometric cue to determination of orientation and curvature at parabolic points. The best advantage taken from this geometric cue is when constraint information can be obtained, knowing absolutely nothing about the reflectance map. The true power of a physical invariant is the information it gives under the most generic conditions possible, in this case any type of smooth reflectance map.<>
Starting Page	344
Ending Page	349
File Size	628843
Page Count	6
File Format	PDF
ISBN	0818620579
DOI	10.1109/ICCV.1990.139547
Language	English
Publisher	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Publisher Date	1990-12-04
Access Restriction	Subscribed
Rights Holder	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Subject Keyword	Photometry Shape Symmetric matrices Jacobian matrices Reflectivity Equations Computer science Geometry Pixel Image analysis
Content Type	Text
Resource Type	Article

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in